1. Field of the Invention
This invention relates to improvements in ice skates, and in particular, to the type of skate in which a plastic support is provided for holding the blade.
2. Description of the Prior Art
Until recently, conventional skates included, in the case of hockey skates, a fabricated metal tubular runner connected to the sole and heel of the skate boot by a pair of frusto-conical metal members welded or riveted to the tubular runner, and a skate blade held by a pair of downwardly extending flanges from the tubular runner. In the case of figure skates, the blade is thicker, and the complete blade and support members are an integral stamping.
The construction of the metal tubular blade support requires numerous manual operations, and with today's high cost of labour, the skate is rendered expensive.
In recent years, it has been thought that by molding the support portion, including the runner, out of plastics material and inserting the blade into a slot provided in the plastics support, the manual operations would be reduced considerably, thereby reducing the cost of the skates. Examples of such skates are Canadian Pat. No. 585,720, issued Oct. 27, 1959, Kirkpatrick et al, in which a one-piece molded plastics support with a metal blade keyed in the plastics support, was suggested. The support so formed resembles the typical metal tube type support. The blade was anchored or keyed in the plastics support by a series of T-shaped elements provided on the upper edge of the blade and provided with intervening plastics receiving openings which were filled with plastic during the molding operation.
It has been found that a serious disadvantage exists in this method and structure for securing the blades to the plastic body. It has been found that the T-shaped anchors which are subject to severe impact forces cannot be effectively and securely molded into the plastic. The reason for this is believed to be based on the inherent behaviour of plastic which is cast hot and which shrinks when it cools. This shrinking thereby allows for the possibility of gaps around the T-shaped keys necessarily resulting in a weakened support.
Canadian Pat. No. 697,856, Florjancic et al, issued Nov. 17, 1964, describes a plastic support with a stamped blade having upward and side projections as well as apertures so that when the plastic material is molded on the blade, the blade will be properly anchored within the support. Furthermore, a reinforcing bar 24 is required in the plastic material to give the support proper strength.
Canadian Pat. No. 985,322, Tvengsberg, issued Mar. 9, 1976, shows a further version of a skate molded-support which has a plurality of openings in the skate blade such that the molded plastic material will pass through the openings and be integrally molded with the blade.
All of the above patents which show a molded support and a blade connected by means of openings or projections in the blade have an inherent failure in that most suitable plastic material must be heated to 500.degree. F. so that it can flow through a suitable injection orifice to be molded on the blade and to pass through openings or lugs provided on the blade. However, the plastic contracts considerably when cooled. The skate blade, being made of steel, has a much lower rate of contraction when it is cooled and, therefore, the plastic material, when contracting, leaves considerable openings or gaps about the various lugs or openings provided in the skate blade to be keyed or anchored in the plastics material. Thus, the reduced anchoring or keying of the metal lugs of the blade, such as T lugs or strictly square or rectangular outline lugs, or the openings in the Tvengsberg patent, have little remaining plastics material surrounding them.